Reduced Insulin Secretion In Protein Malnourished Mice Is Associated With Multiple Changes In The β-cell Stimulus-secretion Coupling

The mechanism by which protein malnutrition impairs glucose-stimulated insulin secretion in the pancreatic β-cell is not completely known but may be related to alterations in the signaling events involved in insulin release. Here, we aimed to study the stimulus-secretion coupling of β-cells from mice fed with low-protein (LP) diet or normal-protein (NP) diet for 8wkafter weaning. Patch-clamp measurements in isolated cells showed that β-cells from LP mice had a resting membrane potential thatwasmorehyperpolarized than controls. Additionally, depolarizationandgeneration of action potentials in response to stimulatory glucose concentrations were also impaired in β-cells of LP mice. All these alterations in the LP group were most likely attributed to higher ATP-dependent K+ (KATP) channel activity in resting conditions and lower efficiency of glucose to induce the closure of these channels. Moreover, a Western blot analysis revealed higher protein levels of the sulphonylurea receptor of the KATP channel in islets of LP mice. Because β-cell Ca2+ signals depend on electrical activity, intracellular Ca2+ oscillations were measured by fluorescence microscopy in intact islets, indicating a lower response to glucose in the LP group. Finally, cell-to-cell synchrony of Ca2+ signals was analyzed by confocal microscopy. Islets from LP mice exhibited a decreased level of coupling among β-cells, which was probably due to the low expression levels of connexin 36. Therefore, low-protein diet leads to several alterations in the stimulus-secretion coupling of pancreatic β-cells that might explain the diminished insulin secretion in response to glucose in this malnutrition state. Copyright © 2010 by The Endocrine Society.151835433554Venables, M.C., Jeukendrup, A.E., Physical inactivity and obesity: Links with insulin resistance and type 2 diabetes mellitus (2009) Diabetes Metab Res Rev, 25 (SUPPL. 1), pp. S18-S23Rao, R.H., Diabetes in the undernourished: Coincidence or consequence? (1988) Endocr Rev, 9, pp. 67-87López-Jaramillo, P., Enfermedades cardiometabólicas en Iberoamérica: Papel de la programación fetal en respuesta a la desnutrición materna (2009) Rev Esp Cardiol, 62, pp. 670-676Desai, M., Babu, J., Ross, M.G., Programmed metabolic syndrome: Prenatal undernutrition and postweaning overnutrition (2007) Am J Physiol Regul Integr Comp Physiol, 293, pp. R2306-R2314Hales, C.N., Barker, D.J., Type 2 (non-insulin-dependent) diabetes mellitus: The thrifty phenotype hypothesis (1992) Diabetologia, 35, pp. 595-601Carneiro, E.M., Mello, M.A.R., Gobatto, C.A., Bochero, A.C., Low protein diet impairs glucose-induced insulin secretion from and 45 Ca uptake by pancreatic rat islets (1995) J Nutr Biochem, 6, pp. 314-318Okitolonda, W., Brichard, S.M., Henquin, J.C., Repercussions of chronic protein-calorie malnutrition on glucose homeostasis in the rat (1987) Diabetologia, 30, pp. 946-951Rao, R.H., Chronic undernutrition may accentuate the β cell dysfunction of type 2 diabetes (1990) Diabetes Res Clin Pract, 8, pp. 125-130Reis, M.A., Carneiro, E.M., Mello, M.A., Boschero, A.C., Saad, M.J., Velloso, L.A., Glucose-induced insulin secretion is impaired and insulininduced phosphorylation of the insulin receptor and insulin receptor substrate-1 are increased in protein-deficient rats (1997) J Nutr, 127, pp. 403-410Heywood, W.E., Mian, N., Milla, P.J., Lindley, K.J., Programming of defective rat pancreatic β-cell function in offspring from mothers fed a low-protein diet during gestation and the suckling periods (2004) Clinical Science, 107 (1), pp. 37-45. , DOI 10.1042/CS20030350Hugh-Jones, P., Diabetes in Jamaica (1955) Lancet, 269, pp. 891-897Ferreira, F., Barbosa, H.C.L., Stoppiglia, L.F., Delghingaro-Augusto, V., Pereira, E.A., Boschero, A.C., Carneiro, E.M., Decreased Insulin Secretion in Islets from Rats Fed a Low Protein Diet Is Associated with a Reduced PKAα Expression (2004) Journal of Nutrition, 134 (1), pp. 63-67Giozzet, V.A., Rafacho, A., Boschero, A.C., Carneiro, E.M., Bosqueiro, J.R., Dexamethasone treatment in vivo counteracts the functional pancreatic islet alterations caused by malnourishment in rats (2008) Metabolism, 57, pp. 617-624Filiputti, E., Ferreira, F., Souza, K.L., Stoppiglia, L.F., Arantes, V.C., Boschero, A.C., Carneiro, E.M., Impaired insulin secretion and decreased expression of the nutritionally responsive ribosomal kinase protein S6K-1 in pancreatic islets from malnourished rats (2008) Life Sci, 82, pp. 542-548Latorraca, M.Q., Reis, M.A., Carneiro, E.M., Mello, M.A., Velloso, L.A., Saad, M.J., Boschero, A.C., Protein deficiency and nutritional recovery modulate insulin secretion and the early steps of insulin action in rats (1998) J Nutr, 128, pp. 1643-1649Arantes, V.C., Teixeira, V.P., Reis, M.A., Latorraca, M.Q., Leite, A.R., Carneiro, E.M., Yamada, A.T., Boschero, A.C., Expression of PDX-1 is reduced in pancreatic islets from pups of rat dams fed a low protein diet during gestation and lactation (2002) J Nutr, 132, pp. 3030-3035Delghingaro-Augusto, V., Ferreira, F., Bordin, S., Do Amaral, M.E., Toyama, M.H., Boschero, A.C., Carneiro, E.M., A low protein diet alters gene expression in rat pancreatic islets (2004) J Nutr, 134, pp. 321-327Wolfson, W.Q., Cohn, C., Studies in serum proteinsclinical studies employing rapid chemical fractionation procedures, with particular reference to the frequency and significance of hypoalbuminemia (1948) J Lab Clin Med, 33, pp. 1276-1288Doumas, B.T., Watson, W.A., Biggs, H.G., Albumin standards and the measurement of serum albumin with bromcresol green (1971) Clin Chim Acta, 31, pp. 87-96Eizirik, D.L., Sandler, S., Welsh, N., Cetkovic-Cvrlje, M., Nieman, A., Geller, D.A., Pipeleers, D.G., Hellerstrom, C., Cytokines suppress human islet function irrespective of their effects on nitric oxide generation (1994) Journal of Clinical Investigation, 93 (5), pp. 1968-1974Bonora, E., Manicardi, V., Zavaroni, I., Relationships between insulin secretion, insulin metabolism and insulin resistance in mild glucose intolerance (1987) Diabete et Metabolisme, 13 (2), pp. 116-121Quesada, I., Todorova, M.G., Alonso-Magdalena, P., Beltrá, M., Carneiro, E.M., Martin, F., Nadal, A., Soria, B., Glucose induces opposite intracellular Ca2+ concentration oscillatory patterns in identified α- and β-cells within intact human islets of Langerhans (2006) Diabetes, 55, pp. 2463-2469Alonso-Magdalena, P., Ropero, A.B., Carrera, M.P., Cederroth, C.R., Baquié, M., Gauthier, B.R., Nef, S., Nadal, A., Pancreatic insulin content regulation by the estrogen receptor ER α (2008) PLoS One, 3, pp. e2069Rafacho, A., Marroquí, L., Taboga, S.R., Abrantes, J.L., Silveira, L.R., Boschero, A.C., Carneiro, E.M., Quesada, I., Glucocorticoids in vivo induce both insulin hypersecretion and enhanced glucose sensitivity of stimulus-secretion coupling in isolated rat islets (2010) Endocrinology, 151, pp. 85-95Nadal, A., Quesada, I., Soria, B., Homologous and heterologous asynchronicity between identified α-, β- and δ-cells within intact islets of Langerhans in the mouse (1999) Journal of Physiology, 517 (1), pp. 85-93. , DOI 10.1111/j.1469-7793.1999.0085z.xTudurí, E., Marroquí, L., Soriano, S., Ropero, A.B., Batista, T.M., Piquer, S., López-Boado, M.A., Quesada, I., Inhibitory effects of leptin on pancreatic α-cell function (2009) Diabetes, 58, pp. 1616-1624Kubista, M., Andrade, J.M., Bengtsson, M., Forootan, A., Jonák, J., Lind, K., Sindelka, R., Zoric, N., The real-time polymerase chain reaction (2006) Mol Aspects Med, 27, pp. 95-125Ashcroft, F.M., Rorsman, P., ATP-sensitive K+ channels: A link between B-cell metabolism and insulin secretion (1990) Biochemical Society Transactions, 18 (1), pp. 109-111Soriano, S., Ropero, A.B., Alonso-Magdalena, P., Ripoll, C., Quesada, I., Gassner, B., Kuhn, M., Nadal, A., Rapid regulation of K(ATP) channel activity by 17β-estradiol in pancreatic β-cells involves the estrogen receptor β and the atrial natriuretic peptide receptor (2009) Mol Endocrinol, 23, pp. 1973-1982Gopel, S., Kanno, T., Barg, S., Galvanovskis, J., Rorsman, P., Voltage-gated and resting membrane currents recorded from B-cells in intact mouse pancreatic islets (1999) Journal of Physiology, 521 (3), pp. 717-728Gylfe, E., Ahmed, M., Bergsten, P., Dansk, H., Dyachok, O., Eberhardson, M., Grapengiesser, E., Westerlund, J., Signaling underlying pulsatile insulin secretion (2000) Ups J Med Sci, 105, pp. 35-51Gilon, P., Henquin, J.C., Influence of membrane potential changes on cytoplasmic Ca2+ concentration in an electrically excitable cell, the insulin-secreting pancreatic B-cell (1992) J Biol Chem, 267, pp. 20713-20720Charollais, A., Gjinovci, A., Huarte, J., Bauquis, J., Nadal, A., Martín, F., Andreu, E., Meda, P., Junctional communication of pancreatic β cells contributes to the control of insulin secretion and glucose tolerance (2000) J Clin Invest, 106, pp. 235-243Ravier, M.A., Güldenagel, M., Charollais, A., Gjinovci, A., Caille, D., Söhl, G., Wollheim, C.B., Meda, P., Loss of connexin36 channels alters β-cell coupling, islet synchronization of glucose-induced Ca2+ and insulin oscillations, and basal insulin release (2005) Diabetes, 54, pp. 1798-1807Sener, A., Reusens, B., Remacle, C., Hoet, J.J., Malaisse, W.J., Nutrient metabolism in pancreatic islets from protein malnourished rats (1996) Biochemical and Molecular Medicine, 59 (1), pp. 62-67. , DOI 10.1006/bmme.1996.0066Martín, M.A., Fernández, E., Pascual-Leone, A.M., Escrivá, F., Alvarez, C., Protein calorie restriction has opposite effects on glucose metabolism and insulin gene expression in fetal and adult rat endocrine pancreas (2004) Am J Physiol Endocrinol Metab, 286, pp. E542-E550Rasschaert, J., Reusens, B., Dahri, S., Sener, A., Remacle, C., Hoet, J.J., Malaisse, W.J., Impaired activity of rat pancreatic islet mitochondrial glycerophosphate dehydrogenase in protein malnutrition (1995) Endocrinology, 136, pp. 2631-2634Filiputti, E., Rafacho, A., Araújo, E.P., Silveira, L.R., Trevisan, A., Batista, T.M., Curi, R., Carneiro, E.M., Augmentation of insulin secretion by leucine supplementation in malnourished rats: Possible involvement of the phosphatidylino-sitol 3-phosphate kinase/mammalian target protein of rapamycin pathway (2010) Metabolism, 59, pp. 635-644Vieira, E.C., Carneiro, E.M., Latorraca, M.Q., Delguingaro-Augusto, V., Amaral, M.E.C., Bosqueiro, J.R., Boschero, A.C., Low protein diet confers resistance to the inhibitory effects of interleukin 1β on insulin secretion in pancreatic islets (2001) Journal of Nutritional Biochemistry, 12 (5), pp. 285-291. , DOI 10.1016/S0955-2863(01)00140-1, PII S0955286301001401Hales, C.N., Non-insulin-dependent diabetes mellitus (1997) Br Med Bull, 53, pp. 109-122Hales, C.N., Barker, D.J., The thrifty phenotype hypothesis (2001) Br Med Bull, 60, pp. 5-20Okitolonda, W., Brichard, S.M., Pottier, A.M., Henquin, J.C., Influence of low- And high-protein diets on glucose homeostasis in the rat (1988) British Journal of Nutrition, 60 (3), pp. 509-516. , DOI 10.1079/BJN19880123Rafacho, A., Giozzet, V.A., Boschero, A.C., Abrantes, J.L., Cestari, T.M., Carneiro, E.M., Bosqueiro, J.R., Reduced pancreatic β-cell mass is associated with decreased FoxO1 and Erk1/2 protein phosphorylation in low-protein malnourished rats (2009) Braz J Med Biol Res, 42, pp. 935-941Martín, M.A., Alvarez, C., Goya, L., Portha, B., Pascual-Leone, A.M., Insulin secretion in adult rats that had experienced different underfeeding patterns during their development (1997) Am J Physiol, 272, pp. E634-E640Wilson, M.R., Hughes, S.J., Impaired glucose-stimulated insulin release in islets from adult rats malnourished during foetal-neonatal life (1998) Mol Cell Endocrinol, 142, pp. 41-48Seino, S., Miki, T., Physiological and pathophysiological roles of ATP-sensitive K+ channels (2003) Prog Biophys Mol Biol, 81, pp. 133-176Yan, F.F., Casey, J., Shyng, S.L., Sulfonylureas correct trafficking defects of disease-causing ATP-sensitive potassium channels by binding to the channel complex (2006) J Biol Chem, 281, pp. 33403-33413Hernández-Sánchez, C., Basile, A.S., Fedorova, I., Arima, H., Stannard, B., Fernandez, A.M., Ito, Y., LeRoith, D., Mice transgenically overexpressing sulfonylurea receptor 1 in forebrain resist seizure induction and excitotoxic neuron death (2001) Proc Natl Acad Sci USA, 98, pp. 3549-3554Calabrese, A., Zhang, M., Serre-Beinier, V., Caton, D., Mas, C., Satin, L.S., Meda, P., Connexin 36 controls synchronization of Ca2+ oscillations and insulin secretion in MIN6 cells (2003) Diabetes, 52, pp. 417-42